Sökning: "conserving approximations"
Hittade 3 avhandlingar innehållade orden conserving approximations.
1. Static and Dynamic Correlation Effects in Atoms
Sammanfattning : The thesis considers the effects of electron correlation by studying the two opposite limits of atoms in the ground state and atoms in strong laser pulses. Computational methods and theoretical approaches differ significantly due to the different physical processes that are studied in these two cases. LÄS MER
2. Model Vertices Beyond the GW Approximation
Sammanfattning : We study the effects of local vertex corrections to the self energy of the electron gas. We find that a vertex derived from time-dependent density-functional theory can give accurate self energies without including the explicit time dependence of the exchange-correlation potential provided, however, that a proper decay at large momentum transfer (large q) is built into the vertex function. LÄS MER
3. Comparative treatment planning in external radiotherapy of malignant tumours : Potential gains using protons
Sammanfattning : It is well known that protons have physical characteristics superior to conventional radiation qualities in external beam radiotherapy. The primary aim of this work is to determine if the physical advantages also may lead to clinical advantages. LÄS MER
